Medical retrieval baskets are used to retrieve biological and foreign material (such as stones) from the body. Some of these baskets may be used through an endoscope or a laparoscope. Stones or other biological materials are captured in the basket by moving the basket around the material to be retrieved, and maneuvering the material into the basket through spaces defined between basket legs.
However, it can be difficult to release captured material from such retrieval baskets, if such release is required or otherwise intended or relevant. Also, in some patients with long-standing clinical problems with urinary tract stones, a cicatrix may form in the tract as a result of trauma to its lining. The stenosis created by the cicatrix may not be so narrow as to interfere with insertion of a retrieval basket while the basket is in a closed position. However, after the basket is expanded to capture a stone that is lodged beyond the stenotic area of the tract, the diameter of the basket with the captured stone disposed therein may exceed the diameter of the stenotic region of the urinary tract. Under these circumstances, the stone needs to be released from the basket in order to withdraw the device from the urinary tract. If the stone cannot be released, then more invasive, surgical approaches are required to disengage the stone from the basket.
Also, in order to capture stones, related art baskets must be eased beyond the stone or to one side of the stone. This maneuver can be technically very difficult. The narrow diameter of the tract lumen, compounded by the formation of stretch resistant scar tissue in the tract at the sites of the stone, can limit or even severely limit the space around which the basket can maneuver. Moreover, the tract lining may become so attenuated at the site of the stone that advancing the basket to one side of the stone may risk rupture of the tract.
The present disclosure addresses one or more of the problems noted above and/or other problems in the art.